155561000665 has 8 divisors (see below), whose sum is σ = 213340800960. Its totient is φ = 106670400432.

The previous prime is 155561000659. The next prime is 155561000669. The reversal of 155561000665 is 566000165551.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 155561000665 - 2³ = 155561000657 is a prime.

It is a super-2 number, since 2×155561000665² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (155561000669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2222299975 + ... + 2222300044.

It is an arithmetic number, because the mean of its divisors is an integer number (26667600120).

Almost surely, 2^155561000665 is an apocalyptic number.

It is an amenable number.

155561000665 is a deficient number, since it is larger than the sum of its proper divisors (57779800295).

155561000665 is an equidigital number, since it uses as much as digits as its factorization.

155561000665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4444600031.

The product of its (nonzero) digits is 135000, while the sum is 40.

The spelling of 155561000665 in words is "one hundred fifty-five billion, five hundred sixty-one million, six hundred sixty-five", and thus it is an aban number.